Nissan is betting heavily on the new Leaf to reassert its electric-vehicle leadership

TOKYO—A month before the introduction of Nissan Motor Co.’s new electric-powered Leaf model, leaked photos from inside the factory where the car is being built have given a good glimpse of what it looks like despite Nissan’s best efforts to keep it under wraps.

Nissan is betting heavily on the new Leaf to reassert its electric-vehicle leadership, which has been much touted by Chairman Carlos Ghosn.